Method and apparatus for renewing the perforations of motion picture films



Nov. 5, 1940. N. KAGANSKI METHOD AND APPARATUS FOR RENEWING THE PERFORATIONS OF MOTION PICTURE FILMS Filed Sept. 17, 1958 77 A47 a/MM hrel fof 44 w w w I N hN NW Wm Q Patented Nov. 5, 1940 YUNITED STATES METHOD AND APPARATUS FOR RENEWING THE PERFOR-ATIONS OF MOTION PICTURE FIIMS Nochoum Kagan'ski, Paris, France Application September 17, 1938, Serial No.-.230,522

InFrance May 23,1938

9 Claims. (01. 164-89) It is an observed fact that motion picture films are provided with perforations which are usually situated at the edges, either symmetrically on both edges of the films, or on a single edge, and

"i which may also be situated at the middle part of the films, between the pictures.

Such perforations, whose number is equal to or a multiple of the number of motion pictures, are adapted for the driving of the films by means 10. of claws or toothed drums, during the whole series of their manufacturing operations, and in the projection apparatus for subsequent public performance.

Thus the good quality of a positive print will depend directly upon the quality of its perforations, and if these latter should become changed for any reason, and should show broken or torn parts, these will rapidly increase until the film is entirely broken by the mechanical effect of the driving teeth which act upon their edges both by bending and by shearing.

The great fragility of the perforations which show starting points for breakage, is due to the nature of the film itself. The film consists, in

25, fact, of a band of transparent plastic material, of some 0.13 mm. thickness, termed the backing, which is covered on one or both sides with a thin coating of gelatine of about 0.015 mm. thickness, which carries the motion pictures.

The backing forms the part of the film representing its strength and flexibility. It usually consists of plastic material, largely composed of cellulose esters, and it thus possesses all the properties of such plastic material. Oneof the principal features of-this plastic material consists in its great resistance to mechanical forces, this being directly due to the great elongation (30 to to which it can be subjecte'd'before breaking. Thus the said backing is adapted to 40 furnish an amount of work which is greater according as this elongation is greater and takes place under a greater force. a

On the contrary, when the said backing has iven the maximum amount of work of which it is capable it will break. Accordingly, when the perforation of a film begins to break, which is evidenced by slight notches appearing on the edges of the films subject to the action of the driving teeth, the perforation is notched, and

such notches are the starting points of torn places which will very rapidly increase.

The present invention has for its object a method for the renewal of theperforations .01

motion picture films which serves to counteract the premature wear of the films caused by the breakage of their perforations. The said process consists in the removal, from the edgesof ,the perforations, of the parts of the backing which have become worn by the action of thedriving teeth, before the occurrence of breakage or tear- In technical language, this time is the one at which the elongation of the material will produce a permanent deformation.

, This removal of'the worn parts of the perforations is efi'ected upon the periphery of the perforations subject to the permanent deformation, by cutting off, by means of ,a punch of the same size, as the "perforated hole, or of a greater size, v a thin strip of the materialof the film.

It is feasible to employ for, this purpose a punching machine which operates by separate perforations, and. to effect the driving of the film by a claw mechanism of the known type which 1 acts by driving the film forwardby'bearing upon the front transverseedges of the original perforations-which are to be renewed.

The invention has further for its object a ma chine adapted for the use of the aforesaid meth- 20 0d for the renewal of film perforations, which machine is chieflycharacterized by the fact that it comprises apunch, or a set of punches, corresponding to the number of film perforations situated on a given transverse line, which 25 punch or set of-punches is combined with a die or a set of dies and with means provided with claws adapted to effect the forward travel of the film by driving it towards the said punch or punches. 1 3:0 The. invention has further for its object the films whose perforations have been renewed by the process above mentioned.

Inthe accompanying drawing, which is given solely by wayof example:

Figs. 1 to 6 represent, on alarge scale, perforations of the film before and after the renewal.

'lis a vertical lengthwise section, of a very diagrammatic nature, of an improved machine for punching the films, adapted for the 4 renewal of film perforations.

Fig. 8 is'a vertical section, on a larger scale,

' on the line 8-8 of Fig. 9, of the punching head.

Fig. 9 is a corresponding plan view, also showing a portion of the film. 45

In order to renew the perforations of the film it is possible either to punch the film I entirely aroundthe original perforation 2 according to the dotted line (Fig. 1), or by cutting off more, or simply at 4 and 5 from the side or sides on which the'notches of deformation have been produced-{Figs 2 and 3). The reerfor'ation may also be efiected by cutting, om a 4 and 6 from the long transverse 55 sides. of the perforation (Fig. 4), i. e., according to the length of thefilm, in order to avoid encroaching, towards the interior, upon the pictures or the soundtrack, or again, both from the transverse; sides andithe outer edge, the ob- 60;

the enlargement 'of'the original perforation, but

this is rather an advantange from a mechanical standpoint, provided a sufficient amount of material is left between theperforationsi and the edges of the film, or between two perforations- The renewal will evidently be more useful at the time when the perforation begins to show damage; it may also be effected in a systematic manner after a certain time of operating.

It is further advantageous to effect this reperforation when the perforations of the film have been subjected to an excessive strain during the printing of the film, "=as is'-infact the case with films in natural colours which are produced by successive printing operations, which are repeated-as many times-as? there are used colours for the procssJ It may be useful in this latter-case, and this is oneof the objects of the" invention, to employ, for use the printing of the film, perforations! of small size (Fig.5) which are then, after the complete finishing-of, the positive copy, enlarged at 18 t'othe' usual-size fo'r-utilization, by-re-perforation-.- This-makes it possible to make a second re-perforation of the films during the period of their use, and thus to increase the duration" of the production-ofpositive copies havinga very high price 4 It may further be useful to' begin the utilization of the film with perforations' 'such as; 9 (Fig. 6) which are smaller than the present standard perforations, and having for instance a less width, in order to afford a' greater'lat'itude during the re-perforation' at l--(Fig. 6)-. This is possible'due to the fact that the normal width of the perforations has'been' madesufficient in order that after the wear" due to the utilization, the engagement 'on the toothed drums will still take place without any abnormal strain.

re-perforati-on may be effected by the use 'of a perforating machine of the same kindas are used for the first perforation of new films, this machine being provided with devices for regulating the distance between the perforations, and if necessary, the distance between the punching tools (and chiefly when the film has several perforations on agiven transverse line) according to the pitch and the spacing of the perforations of the film subject to the re-perfo'ration; Obviously, the punching tools should conform'to the size of the desired re-perforation.

As above stated, a practical'disposition according to the invention consistsin the mounting of the claws for driving thefilm in front of the point where the film,travels under the punching tool or tools, in such way that, the film shall be accurately matched when the perforation or perforations are in the proper position under the punch or punches used for the re-perforation. In this way, the film' will be driven towards the punch or punches, instead of being drawn forward as in the usualperforations.

' Figs; '7 [to 9 represent a machine embodying the above-mentioned considerations, which is adapted for the re-perforatiomat each stroke, of asingle transverse'rowof perforations, i. e., in the case of a standard film of 35 mm. width, two holes which are situated at the same level adjacent the'two' edges of the film.

- In this embodiment, the machine comprises, at-the end of frame II, a reell2 adapted for the unwinding of the film l to be re-perforated. The said film travels through a toothed feeding device l3 which is rotated in the direction of the arrow'f and it forms 'a loop 14, then proceeding into the guide l5, being then re-perforated in the vertical transverse plane XX, at

. which point it travels between the die and the punch-carrier [1.

After the re-perforating process, it leaves the guide at l8, then forms a. loop [9, after which it proceeds through a device for regulating the winding, and then proceedsto the friction winding reel 2|.

The'intake guide 5 is provided with centeringdevices, known per se, which provide for an exact coincidence between the longitudinal axis of 1' the film and the longitudinal axis of the punch carrier I1". i

In the said intake guide I5, the film I is given an alternate longitudinal driving movement whichibrings each lateral line of perforations 2 successively before the punch-carrier I! and the die Hi. This movement is imparted to the'film by the claws 22 which are given a reciprocating motion by any suitable device. In the embodiment herein represented, the mechanism for op-' erating the claws comprises-in the known man ner, a heart-shaped cam 23 keyed to a transverse rotatable shaft 24. The said cam rotates in a movable frame 25, which is thus given four successive movements in directions which are at right-angles to one another, corresponding respectivelyto the insertion of the claws into the film, to the horizontal driving of the film from left to right, to the downward withdrawal of the clawsfand to' the return of the claws to the initial position in the rear.

' The said claws 22 should have such position relatively to the axis of the shaft 24 of the cam 23, that the said clawswhich drive the film by the forward edge of the perforations 2 will be removed from the film, when they are withdrawn,according to a line Y-Y (Fig. 9) in such conditions that this line shall be located at a Well defined distancea: from the axial transverse plane X-X of the punches, and this distance will vary according to the pitch, which is also variable, of the-perforations of the film.

in the case of the standard film, thetheoretical' pitch is 4.75 'mm., but owing to the shrinkage of the film during the operations of printing, developing, etc. and during the utili zati'on', thispitch may be reduced to a distance beloy 4.70. mm. In order to provide for the. adjustment of the distance :r, the claws 22 are displaced with reference to the axis of the shaft 24 of the cam 23. For this purpose, the claws 22 are securely mounted on a claw-carrier 26; which is adjustableupon theframe 25 of the heart-shaped cam 23. The said claw-carrier 26 has an appendage consisting ofa rod 21 uponwhich is mounted a nut 28 cooperating witha micrometric screw 29 which is rotatable, but without lengthwise displacement, in a member 30 which is rigidly secured o the frame 25 of the cam 23. It will be noted that it is simply necessary to turn the screw29 in order that thenut 28 and with it the claw-carrier 26 shall be displaced lengthwise with reference to the fram'ef25.

Injo'rder to provide for the right-angled move-' ment of the claws 22, the device may be pivotally mounted on journals 31 secured to the nut 28 and sliclable'in 10m 32 formed in the main frame.

The means for lengthwise adjustment above described are-preferably accompanied by means for the transverse adjustment of the distance between the punches, according to the transverse spacing of the perforations 2 of the film I. Such means may consist, for example, of the mounting of each punch 52, provided with a stiffening sleeve 33, in a block 34, in which it is held by a screw 35. The two blocks 34 are movable, horizontally and crosswise, in a frame I! in which they are held for instance by stopplates 36, and they may be displaced in the said frame for instance by means of a micrometer screw 37 provided with two screwthreads having contrary directions. The said screw 31 is rotatable in the frame If, and the two blocks 34 form nuts for the two respective screwthreads, and thus by turning the said screw, the two punches 52 can be brought nearer together or separated.

The frame H is connected with a suitable mechanism by which it can be given a vertical alternate movement. This frame I! is connected, for instance by uprights 38 slidable in the machine frame II, with the strap 39 of an eccentric 40 which is keyed to the driving shaft 4|.

Obviously, the said invention is not limited to the embodiments herein described and represented, which are given solely by way of example.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. A method for renewing the perforations of motion picture films which .consists in providing the film with perforations smaller than the usual standard perforations, feeding the film through at least one kinematograph apparatus, and removing from the edges of the perforations the parts which have been worn by the action of the driving teeth.

2. An apparatus for renewing the perforations of motion picture films comprising guiding means for the film, punching means adapted to cooperate with said guiding means and to renew the perforations of a film in said guiding means, and intermittent film feeding means adapted to be brought into and out of engagement with the perforations to be renewed in the film and to push said film stepwise towards said punching means.

3. An apparatus for renewing the perforations of motion picture films comprising guiding means for the film, punching means adapted to cooperate with said guiding means and to perforate a film in said guiding means, intermittent film feeding means adapted to be brought into and out of engagement with the perforations to be renewed in the film and to push said film stepwise towards said punching means, and means adapted to adjust the distance between said film feeding means and said punching means.

4. An apparatus for renewing the perforations of motion picture films comprising guiding means for the film, punching means adapted to cooperate with said guiding means and to perforate a film in said guiding means, intermittent film feeding means adapted to be brought into and out of engagement with the perforations to be renewed in the film and to push said film stepwise towards said punching means, and means adapted to adjust the position of said punching means transversely with relation to said film guiding means.

5. An apparatus for renewing the perforations of motion picture films comprising guiding means for the film, at least one die on one side of said guiding means and at least one punch on the other side of said guiding means for renewing the perforations of a film in said guiding means, means adapted to move said punch towards and away from said die through said guiding means, a movable claw carrier, at least one claw on said .carrier, adapted to engage perforations of the film and to be removed from said perforations during the movements of said claw carrier, and driving means adapted to move said claw carrier along a closed path and to push said film towards said die and said punch when said claw is engaged in a perforation.

6. An apparatus for renewing the perforations of motion picture films comprising guiding means for the film, at least one die on one side of said guiding means and at least one punch on the other side of said guiding means, means adapted to move said punch towards and away from said die through said guiding means, guiding ways in parallel relation with said guiding means for said film, an axle adapted to be displaced in said guiding ways, a movable claw carrier pivotally mounted on said axle, at least one claw on said .carrier adapted to engage perforations of the film and to be removed from said perforations during the movements of said claw carrier, a frame on which said claw carrier is adapted to slide in a direction parallel to said guiding means and guiding ways, adjusting means adapted to vary the relative position of said claw carrier and of said frame in a direction parallel to said guiding means and guiding ways, and driving means adapted to move said frame along a. closed path and to push said film towards said die and said punch when said claw is engaged in a perforation.

7. An apparatus according to claim 6, in which said adjusting means consists of a screw-threaded rod rotatably mounted in said frame and engaging sail claw carrier, whereby said claw carrier is adapted to be moved along said rod when said rod is rotated.

8. An apparatus for renewing the perforations of motion picture films comprising guiding means for the film, at least two dies on one side of said guiding means disposed in a transversal plane at right angles with said guiding means, at least.

two punches on the other side of said guiding means disposed in the same transversal plane, means adapted to move said punches towards and away from said dies through said guiding means, adjusting means adapted to move said punches towards and away from each other, a movable .claw carrier, at least two claws on said carrier dis-posed transversely with relation to said guiding means in a plane at right angles with said guiding means and adapted to engage perforations of the film and to be removed from said perforations during the movements of said claw carrier, and driving means adapted to move said claw carrier along a closed path and to push said film towards said dies and punches when said claws are engaged in perforations.

9. An apparatus according to claim 8, in which said adjusting means consists of a rod provided with two screwthreads having contrary directions and engaging said punches respectively with said screwthreads.

NOCHOUM KAGANSKI. 

